Alarm lock



May 7, 1940. s. MAIDA, JR,

ALARM LOCK Filed NOV. 15, 1938 7 J6 INVENTOR. 1] 0% aztmlaa JR. 2 ATTORNEY.

Patented May 7, 1940 ALARM LOCK Gaetano Maida, In, New York, N. Y.

Application November 15, 1938, Serial No. 240,448

1 Claim.

This invention relates to looks of all kinds, and its object is to provide a novel circuit-closing means contained withinthe lock, whereby an audible or visual alarm of any kind may be ac- 5 tuated as soon as the lock is opened.

The above and other objects will become apparent in the description below, in which characters of reference refer to like-named parts in the accompanying drawing.

Referring briefly to the drawing,

Figure l is a view illustrating the alarm clock applied to a house door.

Figure 2 is a view of the lock with its cover plate removed, showing the hasp in locked position.

Figure 3 is a View similar to Figure 2, showing the hasp in sprung position.

Figure 4 is an enlarged fragmentary view, partly in section, of the left-hand side of the lock of Figure 3.

Figure 5 is a cross-sectional view taken on the line 55 of Figure 2.

Figure 6 is a fragmentary cross-sectional taken on the line 66 of Figure 4.

Referring in detail to the drawing, the numeral l represents the annular housing of a hasp lock having the two cover plates II and I2, into which the key I3 is, as is customary, insertable from the bottom. The bolt M has its arm slidably mounted in an opening in the housing "I, and a coiled spring I6 normally urges the arm l5 upward. As the lock per se may be of any standard type of construction, and it is not desired to claim any part of the same, further unimportant details of the lock per se will not be described.

, The arm|5 of the bolt l4, however, is modifled from the standard construction by providing a peripheral groove I1 thereon intermediate its length. Within the housing l0, one end of a strip of firm insulation I8 is anchored to the roof of the housing by a screw or rivet H], with one end of a spring contact finger 20 secured between the rivet l9 and the insulation I8. At its other end the strip l8 has a rivet 2| passing therethrough, and on its lower end a metallic contact button 22 is integral with the rivet 2|. On its top end the rivet 2| retains a spring terminal 23 against the strip H3, in electrical contact with 50 the rivet 2| and the button 22. The free end of the finger 20 is concavely rounded to provide a yoke 24 which registers loosely in the groove H of the hasp arm |5. An insulated wire 25 has its end attached to the spring terminal 23, 55 and passes through a hollow metallic tube 21 into an armored sleeve 26 out of the housing l0, through an opening in the latter. The tube 21 has a flange 28 on its free end, by means of which it is prevented from being pulled through the said opening, and the protruding end of its stem has a flange 30 rotatably locked in the nut 29 on the end of the armored sleeve 26. It is thus obvious that the sleeve 26 cannot be detached from the lock housing without cutting through the sleeve.

The spring finger 20 is, as is apparent, grounded to the housing It! by the rivet I9; the armored sleeve 26, as is also apparent, is also in electrical contact with the housing Ill and is used as one of the conductors of the circuit leading from the lock to the alarm unit. The latter comprises a relay 3| having one terminal lead by a wire 32 to the sleeve 26 and its other terminal lead by a Wire 33 to one terminal of the battery 33; the other battery terminal is connected by a wire 34 to the wire 25. It is thus apparent that, when the circuit between the finger 20 and the button 22 isclosed, the relay 3| will be actuated. The armature 35 of the relay is pivoted at its lower end, at 36. A coiled spring 31 is anchored at its lower end at a point 39 beyond the pivot 36 and. has its upper end attached at 38 to the armature; it is to be noted that the points 38, 36, and 39 are in alignment when the armature is in its inactive position, so that the spring 31 will tendto preserve that position. Upon energization of the relay, the armature will swing toward the relay to bring its head 40 against the contact 4|, and in the latter position of the armature the spring 31 will also tend to preserve the position, so that in order to open the contact between the members 40 and 4| it will be necessary to move the armature back by hand. Thus, once the relay is energized the members 40 and 4| are brought into mutual contact and will remain so until separated by hand.

The armature 40 is connected by the wire 42 to one terminal of the alarm 43; the contact 4| is connected by a wire 44 to one terminal of the battery 33. The other terminal of the alarm 43 is connected by a wire 45 to the other terminal of the battery 33. The other terminal of the alarm 43 is connected by a wire 45 to the other terminal of the battery 33. Hence, When the relay has been energized, the alarm 43 will be actuated and will continue actuated until the members 40 and 4| have been manually separated, as above-mentioned.

The circuit through the relay is closed by the finger 20 being brought against the button 22 when the hasp arm I5 rises upon turning of the key l3, as the yoke 25 will then be carried up in the groove H. The circuit is then again opened by closing the lock. In the event that the armored sleeve 26 be cut with a knife or shears, a short circuit will occur between the cutting tool, the sleeve 26 and the wire 25, thus also energizing the relay and the alarm.

Obviously, modifications in form and structure may be made without departing from the spirit and scope of the invention.

I claim:

In a lock comprising a housing having a bolt or the like adapted to be moved longitudinally from, one position when the lock is closed to antion mounted in said housing at right angles to said bolt, a contact button on the end of said strip opposite said bolt, a spring finger having one end secured to the opposite end of said strip and normally extending angularly with respect to said strip to provide a space between the other end of said strip and said button, the extremity of said finger registering loosely in said groove and being adapted to be swung alternately into and out of contact with said button with the said movement of said bolt, said button and said strip being adapted to form the two poles of an alarm circuit, the said extremity of said finger registering in said groove being concavely rounded to form a yoke.

GAETANO MAIDA, JR. 

